1. Field of the Invention
The present invention relates to a method for preparing aluminum-containing crystalline zeolites having the IFR structure (“IFR zeolite”) using a zeolite as an active source of aluminum oxide.
2. State of the Art
IFR zeolites are known. U.S. Pat. No. 5,437,855, issued Aug. 1, 1995 to Valyocsik, discloses a zeolite, designated “MCM-58”, having the IFR structure prepared using a benzylquinuclidinium organic directing agent. However, it does not disclose the use of a zeolite as a source of aluminum for MCM-58. U.S. Pat. No. 5,441,721, issued Aug. 15, 1995 to Valyocsik, also discloses MCM-58, but prepared using a benzyltropanium organic directing agent. Use of a zeolite as the source of aluminum for MCM-58 is not disclosed. It has been discovered that when a zeolite (Na—Y) is used as the source of aluminum and benzyltropanium is used as the structure directing agent, the only zeolite produced was FAU (a starting material). No zeolite with the IFR structure was made (see Comparative Example B below). Both patents are incorporated by reference herein in their entirety. U.S. Pat. No. 5,653,956, issued Aug. 5, 1997 to Zones, discloses a zeolite, designated SSZ-42, prepared using an organic templating agent selected from the group consisting of 1-benzyl-4-aza-1-azonia-bicyclo[2.2.2]octane cations and N-benzyl-1-azabicyclo[2.2.2]octane cations. The SSZ-42 may contain oxides of boron, aluminum, gallium, iron or titanium, but at least 50% of those oxides must be boron oxide. Zeolites are disclosed as a possible source of aluminum or boron (see col. 8). In Example 14, an aluminum-containing SSZ-42 is made, but the aluminum is added to the SSZ-42 by post-treatment after the boron-containing SSZ-42 was prepared. Likewise, in Example 16 a boron- and gallium-containing SSZ-42 is made by adding gallium by post-treatment of previously made SSZ-42. In Example 20, an aluminum-and boron-containing (50/50) SSZ-42 is prepared directly using sodium borate as the source of boron and sodium aluminum trihydrate as the source of aluminum. U.S. Pat. No. 5,653,956 is incorporated herein by reference in its entirety.
U.S. Pat. No. 5,340,563, issued Aug. 23, 1994 to Zones et al., discloses an improved method for preparing large pore zeolites. The method involves preparing a reaction mixture containing a source zeolite, an alkali metal, nitrogen containing organic cation, a source of silica and water. The source zeolite contains sodalite substructures and has a tetrahedra atom density of less than about 15 TO2 per 1000 Angstroms3. Examples of zeolites prepared by this method are SSZ-25, SSZ-31, SSZ-37, beta and ZSM-12. Zeolites A, N-A, ZK-4, faujasite, X, Y, ZK-5 and rho are disclosed as source zeolites. U.S. Pat. No. 5,340,563 is incorporated by reference herein in its entirety.
U.S. Pat. No. 4,503,024, issued Mar. 5, 1985 to Bourgogne et al., discloses synthesizing zeolites using zeolites as reactants. It does not, however, disclose the synthesis of a zeolite having the IFR structure.